quote:

Originally posted by danalinscott:

quote:

OK does that mean you know that the pan test doesn't work to show suspended water? If so then I think lots of people may have suspended water problems they don't know about.

quote:

The pan test is what I thought was best (better than the "crackle test"), but maybe Dana doesn't like that test anymore?

Look...I asked you to point me to the testing you did. No need to get testy about this. All I am interested in is that it is thoroughly tested before everyone assumes it removes suspended water.

Now..as I said before ...if you want to give me a hint where the info on testing for water is posted I would appreciate it. I was unable to find it when I looked.

Sorry if that appeared testy, I don't feel testy. I am just asking questions to clarify what you mean. I mentioned I used the hot pan test in many places in this thread. And that pan test is the one I learned from your posts Dana. I won't repeat it here since I just did in answer to another thread. I just thought maybe you don't like it anymore.

And Bud, does that mean you don't like Dana's pan test?

I just checked the thread for you Dana and I mention the pan test for water on pages 2,3,6 and 7. edit- And JOAT mentions it on a couple pages too.

Okay, the milkiness is only in the beginning. Got it. That clears up some confusion for me (no pun intended). I thought that's what you had said, but it's been awhile since I started reading this thread. I should have looked back earlier in the thread before posting.

Dana, I'm not sure if this is what you're looking for, but Sunwizard said,

"So far there are only 2 of us testing this here. I have run 4 different batches ranging from 15-40 gallons, all mistwashed and I left visible water in the oil. And it was removed in all batches after 4 passes according to the hot pan test."

That was about 10 posts up. Hope that helps.

edit: okay, now it's more like 14 or 15 posts up

Also, I seem to remember reading somewhere you did some testing with a centrifuge that uses the same principle as the dieselcraft and it didn't get the water out --which was why you said it wouldn't work. I would be interested to find out more about the results you got and the different variables in your experimentation (like different temperatures of the oil, etc.) and also what brand the unit you tested was.

What I am interested in is whether the results sunwizard and joat are getting are due to their specific technique or if it is a difference in the design of the unit that's different than the one you tested, or maybe something else. If you hadn't already tried this, maybe you could pull your old centrifuge out and test it out again using the same technique sunwizard is using and see if you get the same results. If you do this, let us know what you find.

If this method proves to be as effective as it is sounding, it would mean a revolutionary advancement in the veg oil movement: truly effective, cheap (in the long run), on-the-go purification of waste oil. Yeah!!!

Very interesting thread here. There is another thread on the biodiesel section using similar equipment to remove soap from biodiesel.

Does Buuuuuud's centrifuge have a larger contaminate capacity that this one and has anyone tried it on separating out glycerine?

sunwizard

I do indeed like dana's fry pan sizzle test. I use it all the time, taking samples as the centrifuge is running. I use it as a test to see if I'm running the oil through the machine to fast. Each batch of oil is different and there fore, at time, the feed speed has to be changed.

I ran a lab test on my oil to see if there was any acid and water in the oil that I was not able to test for and anything else that I should know about the stuff that I was putting in my fuel tank. Also I wanted to know the PPM of any contaminant that did remain in the oil after being centrifuged. I usually run the oil through the machine only once and if there is something wrong, Dana's test will tell me. IMO it is an excellent bench mark to start from.

That's the way we test, here in the West

Buuuuud

Could be that Dana is alluding to testing for *SUSPENDED* water, not just visible water or emulsified water. Evidently suspended water is not always visible to the naked eye (without a microscope). Milky WVO may not necessarily indicate suspended water is present.

Suspended water will show up as small bubbles appearing at the pan surface in a correctly performed hot pan test. But the suspended water has to be present to produce the small bubbles.

The key here seems to be guaranteeing the presence of suspended water in the WVO BEFORE running it thru the centrifuge, and the lack of it afterward. Probably would need close inspection w/ a microscope?

Then I suppose we should prepare to endure revisiting the controversy on whether suspended (invisible to the naked eye?) water causes cavitation damage or not.

Dana & others: Please correct me if I am mistaken.

if you want some WVO with suspended water in it to test with, i will ship you some of mine. it always fails the hot pan test.

and yes, i agree with Carimbo. the right way to test if it is removing suspending water is to run WVO with suspended water in it, through it. adding water to the WVO will not prove it removes suspended water.

quote:

Originally posted by danalinscott:
Visible water is much easier to remove than suspended water. I am not too surprised that it is removed...but if I understand correctly no one has tested to determine if suspended water is removed. Yet..I see folks assuming it will. Even you have recently made statements that it completely removes water from wvo. I am sure it is not your intent to mislead anyone. But people will assume that you have thoroughly tested to back these type of statements if you make such bold statamants.

Maybe it would be best if we discussed how a through test to determine if all water IS removed might be undertaken before everyone assumes it does and begins depending on them to do so.

Dana, I have not fully finished testing yet. I will say it appears to reduce suspended water in my more difficult oils with each pass, using your posted pan testing techniques. I have not determined how many passes would be needed for complete removal, assuming thats possible.

I am going to be doing some tests on some fully centrifuged and filtered oil in the next 2 weeks to see whether or not I can eliminate all signs of bubbles.

My other concern, tho not so critical, is the machined surface on mine is not centered. This means the cover is off center a bit, so oil is heavier on one side, leading to alot of vibration and a loud vacuum cleaner like noise. Maybe not noticeable on a truck, but even rubber mounted it resonated thru the house and I can hear it run from across the street. I had thought of exchanging it to see if I could get a better one but now I see there is a 14 day lead.

It does appear to remove <20 micron solids better than multiple heated settling stages alone did, so my filters are likely to have a much longer life expectancy. Last batch I ran 40 gallons without clogging my improvised Bounty suction side filter. Normally I'd have to change the bounty 2-3 times at a .5 GPM rate.

quote:

Originally posted by JOAT:
My other concern, tho not so critical, is the machined surface on mine is not centered. This means the cover is off center a bit, so oil is heavier on one side, leading to alot of vibration and a loud vacuum cleaner like noise. Maybe not noticeable on a truck, but even rubber mounted it resonated thru the house and I can hear it run from across the street. I had thought of exchanging it to see if I could get a better one but now I see there is a 14 day lead.

Mine is loud also, and a little off center too. It doesn't appear to affect its filtering action. And there is a balancing weight that is welded onto one side of it. I have found that by changing the pressure even a small amount, it changes the RPMs enough to make it much quieter. I think at certain speeds it sets up resonance. Also my new mounting which is not connected to the barrel made it much quieter. You can't hear it across the street anymore

quote:

Originally posted by SunWizard:
Mine is loud also, and a little off center too. It doesn't appear to affect its filtering action. And there is a balancing weight that is welded onto one side of it. I have found that by changing the pressure even a small amount, it changes the RPMs enough to make it much quieter. I think at certain speeds it sets up resonance. Also my new mounting which is not connected to the barrel made it much quieter. You can't hear it across the street anymore

My concern is getting it quiet enough for mobile apps. I'm sure if I mounted it to a pipe set in concrete it would quiet down, but that wouldn't be feasable in a vehicle. I makes everything it touches vibrate.

quote:

Originally posted by Carimbo:
Could be that Dana is alluding to testing for *SUSPENDED* water, not just visible water or emulsified water. Evidently suspended water is not always visible to the naked eye (without a microscope). Milky WVO may not necessarily indicate suspended water is present.
....snip....
Dana & others: Please correct me if I am mistaken.

I'll try to clarify this a bit.

Yes, the suspended water being refered to is not visible to the naked eye. It is much smaller than what you get from an emulsion, sub micron in size. In fact, it is small enough it can exist for long periods of time in a deep fryer without boiling out, tho it may evaporate if it comes to the surface. Since it is sub micron in size, the surface tension of the oil around it prevents it from turning to steam. Also, it is very possible the small size and resulting strong film of oil around them may prevent water washing from having any effect on them. I'd suspect the only way to truly free all the water and disolved contaminants would be with a chemical that was both water and oil soluble (like ethanol). Then a process that could separate the oil from that.


When you do a pan test, you are quickly heating a VERY thin layer to higher temps so the small steam bubbles become visible.

To be specific on how I am doing my pan test:

1st, I heat a thin layer of clean oil in a pan till it starts to smoke. I stir it around a bit to make sure this is no air trapped on the pan to create bubbles. Then I wipe it out till it's just a thin layer.

Next, I reheat it till it smokes, then put about 1/8 teaspoon in a puddle on one side to look for larger bubbles. On the other side I take another 1/8 tsp and smear it across in a thin layer and look for smaller bubbles.

quote:

Originally posted by Mr Dieselcraft:
I suggest someone take a sample of the oil that has been run through the centrifuge and send it to a testing lab. Ask for Water & Sediment by Centrifuge ASTM D2709 100 ml Cost is about $35. I believe this will tell exacting the water content of the sample. Suspended or emulsified water, it will not matter

We use this lab: http://www.herguth.com/testing/method.htm

For any who are interested in lab tests, this powerpoint has a good summary of them:

http://www.cisat.jmu.edu/biodiesel/presentations06/INTE...hie%20Johns~0006.ppt
Slide 18 is ATSM D2709.

Also: http://www.biodieseltesting.com/tests.php

Also: Document#: ASTM D2709-96(2006)
Title: Standard Test Method for Water and Sediment in Middle Distillate Fuels by Centrifuge
Abstract:

1.1 This test method covers the determination of the volume of free water and sediment in middle distillate fuels having viscosities at 40°C (104°F) in the range of 1.0 to 4.1 mm²/s (1.0 to 4.1 cSt) and densities in the range of 770 to 900 kg/m³.

Out of curiosity I called Herguth labs to find out more about how ASTM 2709 is done. Toulene (sp) is added to the sample being tested in a graduated cylinder (test tube with scale marks) and spun in a centrifuge. Water and particulates are then identified visually, i.e. reading of scale. I am waiting on an answer as to the G level the testing is done at.

The centrifuge used for the ASTM 2709 spins at 1875 RPM. I am waiting on an answer from Herguth as to what diameter from center the graduated cylinder is placed. There are 4 equidistant "holes" in the centrifuge where the graduated cylinder is placed, the other 3 is filled with graduated cyl filled with liquid of equal weight for balance.

Anyone know what G level is required to separate suspended water from veg oil? What G level is the Dieselcraft centrifuge capable of?

QUOTE]Originally posted by rackley:

quote:

Originally posted by Mr Dieselcraft:
I suggest someone take a sample of the oil that has been run through the centrifuge and send it to a testing lab. Ask for Water & Sediment by Centrifuge ASTM D2709 100 ml Cost is about $35. I believe this will tell exacting the water content of the sample. Suspended or emulsified water, it will not matter

We use this lab: http://www.herguth.com/testing/method.htm

For any who are interested in lab tests, this powerpoint has a good summary of them:

http://www.cisat.jmu.edu/biodiesel/presentations06/INTE...hie%20Johns~0006.ppt
Slide 18 is ATSM D2709.

Also: http://www.biodieseltesting.com/tests.php

Also: Document#: ASTM D2709-96(2006)
Title: Standard Test Method for Water and Sediment in Middle Distillate Fuels by Centrifuge
Abstract:

1.1 This test method covers the determination of the volume of free water and sediment in middle distillate fuels having viscosities at 40°C (104°F) in the range of 1.0 to 4.1 mm²/s (1.0 to 4.1 cSt) and densities in the range of 770 to 900 kg/m³.[/QUOTE]

quote:

Originally posted by canolafunola:
Anyone know what G level is required to separate suspended water from veg oil? What G level is the Dieselcraft centrifuge capable of?

This centrifuge spins at >6000rpms and produces 2000g according to their website. That makes no difference however for water removal since this rig works like a flash evaporator.

Here is how I do my pan test since it is slightly different from JOATs:

The pan test.
Smear a finger of wvo accross a fry pan (cast iron preferred)as a temp check.

Keep the sample of wvo to be tested handy. Enough for 1/4"-3/8" thickness covering the bottom works best.
Heat the pan on high temp until the smear begins to really smoke then pour in the sample.

NOTE:
Do not pour in a sample with any visible water. If water droplets are visible no testing is needed. There is water present in your sample. Visible droplets of water will spatter hot oil out of the pan and may cause burns or fire.

Look closely at the bottom of the pan where the oil meets it. Are there very small bubbles forming. This indicates some suspended water. The number of bubbles indicates how much water is present in suspended form.

Has this discussion taken place on the flash evaporator threads and I have missed it? Seems like its just as important there, and they have been doing this same kind of testing for much longer.

I wish the Dieselcraft centrifuge could remove suspended water by centrifugal action rather than flash evaporation. If so, the soulble acids are removed along with the water and not left behind, thus not requiring mist wash before centrifuging, which greatly complicates the process, especially in a mobile environment.

Sunwizard and JOAT, can you run a few batches of WVO without mist washing and test for suspended water and acidity?

quote:

Originally posted by SunWizard:

quote:

Originally posted by canolafunola:
Anyone know what G level is required to separate suspended water from veg oil? What G level is the Dieselcraft centrifuge capable of?

This centrifuge spins at >6000rpms and produces 2000g according to their website. That makes no difference however for water removal since this rig works like a flash evaporator.

Has this discussion taken place on the flash evaporator threads and I have missed it? Seems like its just as important there, and they have been doing this same kind of testing for much longer.

quote:

Originally posted by canolafunola:
I wish the Dieselcraft centrifuge could remove suspended water by centrifugal action rather than flash evaporation. If so, the soulble acids are removed along with the water and not left behind, thus not requiring mist wash before centrifuging, which greatly complicates the process, especially in a mobile environment.

Sunwizard and JOAT, can you run a few batches of WVO without mist washing and test for suspended water and acidity?

We are both doing pan tests that supposedly show suspended water, and seeing good results. JOAT, was the nasty oil you used in your tests mist washed?

The acid test would require finding some oil with a known amount of suspended water and acid, run a lab test on it, then run this rig, then run a lab test. I am not prepared to do that. But I think there are some on this board who could run tests like that.

My guess is that acidity, salts or sugars would not be removed by this. Thats another reason I wouldn't spend the money on tests. That is why I mist wash. I have not seen anyone do tests like that on any methods to remove acids, salts, or sugars, have you?

quote:

My guess is that acidity, salts or sugars would not be removed by this. Thats another reason I wouldn't spend the money on tests. That is why I mist wash. I have not seen anyone do tests like that on any methods to remove acids, salts, or sugars, have you?

I really hope this is not true, which makes the Dieselcraft unit much less attractive (to me).

I have not tried it but this is a method I've read about to do the acid test using litmus paper:

In a bottle, add 50 %water to the oil sample you want to test. Turn bottle upside down a few time to mix (do not shake violently to make an emulsion). Let the water separate. Drain off the oil while leaving the water behind. Test the water with litmus paper. This is from memory so please correct me if I am wrong.

So, you would do the litmus test to a sample of WVO before and after running it through the Dieselcraft and compare the color of the litmus papers. Not sure how reliable this test is. Comments? Dana?

I don't have any acidic oil to test. But since this is an evaporative dewatering it seems kind of unlikely.

With any centrifuge it has to be finely tuned and operated to get acids out. (acid and other contaminants have a different specific gravity and probably requires different design or operation than plain water, same for salt, sugars.) Thats why I ask is there anyone who tested oil before and after a centrifuge for acid? I saw Buds test of after only, but that won't tell us much without the before centrifuge tests also, since it could have been no acid, etc. to start with.

Seems like the way to go if you want to avoid mistwash when mobile would be to do your PH test on a sample of the oil before you collect and if its bad, either don't take it and move to another source, or plan on mistwash.

A lot of questions...and very little time for me to respond. Please forgive me (and bring it to my attention in a PM)if I miss any.

A "true" centrifuge will physically separate water from WVO just as settling (after filtering) does. It is just much faster. This water will contain the water soluble acids/salts/sugars/etc it absorbed while it was suspended in the wvo.

Cetrifugal filters will not physically separate water (or the contaminants it carries) from wvo. In fact they will usually tend to emulsify any free water.

Mistwashing will tend to remove suspended water though it seems to often leave a heavier loading of water in place of the suspended water/acids/salts/sugars/etc. it washes out. The "replacement droplets" are on average much larger and tend to settle out..or centrifuge out.. faster than the suspended water (with acid/salt..etc) does.

Mistwashing also tends to remove up to 95% of particulate contamination in wvo. Consequently it is included as a step prior to filtration/dewatering in most commercial wvo fuel processing. It is a relativly simple, low tech, and low cost process.

I suspect it will be worth incorporating in any processing unit which uses the Dieselcraft unit.

Though it is possible that it might concievably be able to remove suspended water without it..I seriously doubt it can. Every time I have tested evaporative dewatering of unwahsed wvo I have found that it was not actually completely dewatered. Even the pan test may not reveal suspended water mixed with highly concentrated amounts of salts/sugars/acids/etc.

This is why I am suggesting discussing testing.
IF the Dieselcraft centrifugal filter/flash evaporator unit that Sunwizard has developed DOES in fact remove even contaminated suspended water completely it would be GREAT to know this. And even if it does not it would still be good to know.

I am NOT attempting to denigrate Sunwizard efforts. To the contrary I am very grateful for the R&D he has accomplished so far. The fact I did not think of combining flash evaporation with a cetrifugal filter (even though I certianly had plenty of opportunity to do so)is simply proof positive I am not a genious....which comes as no surprise to me. And is probably no surprise to most others either.

There is great potential here.
A bit more research and testing may provide the basis for widespread use of that potential.

I suggest (and it is only a suggestion) that those testing the unit try to determine if suspended water(acid/salt/etc) is actually being removed..or just concentrated.

Here is the test I suggest:
Take a sample of wvo with suspended water(5-10 gallons) and process it without mistwashing.

Process an equal amount after mistwashing.

Compare the acidity of both using both titration and the distilled water "wash" (litmus paper) method.

If they test identical I believe it might be strong proof that the method DOES thoroughly dewater without mistwashing. If not it might be helpful to others considering using the unit to always use a wash as an initial step.

quote:

Originally posted by canolafunola:
In a bottle, add 50 %water to the oil sample you want to test. Turn bottle upside down a few time to mix (do not shake violently to make an emulsion). Let the water separate. Drain off the oil while leaving the water behind. Test the water with litmus paper. This is from memory so please correct me if I am wrong.

So, you would do the litmus test to a sample of WVO before and after running it through the Dieselcraft and compare the color of the litmus papers. Not sure how reliable this test is. Comments? Dana?

I've tried this type test repeatedly. Usually there is no change in PH if you do it on clean oil but then the amount of dilution involved would make it dificult to detect the difference with PH paper. Annoyingly tho, I had a few of the tests show a change in the water PH to alkaline! I suspect from a fine powder cleanser in the oil, but thats just speculation... Anyway, without isolating the suspended water and analyzing it directly, any such tests are unreliable for real conclusions concerning washing effects on suspended water. Only it's ability to remove some solubles.